Those backticks are PowerShell's escape character. In this instance, they're escaping the carriage return at the end of the line, turning it from a functional end-of-command indicator into a literal carriage return. In other words, it's serving as a "line continuation" character of sorts. There are two major problems with this approach, I've realized:

That backtick character is really hard to read. In a book, it's easy to mistake it for a stray piece of ink or toner. On-screen, it's just easy to miss. It's, like, 3 pixels.

If there's any white space after the backtick - a space or tab, for example - then THAT will be escaped, not the carriage return. That fact makes it very easy to mess up when you're typing a command in, with the result being improper execution and unexpected error messages.

That's when I realize how smart PowerShell is. Anytime it sees an opening item such as { [ ( ' or " it will let you hit Enter all you want, without actually ending the line, since it knows that you've got more to type. It'll also allow you to hit enter, creating a new physical line but not executing the command, when a line ends in a pipe | or comma character - even if those characters are followed by other whitespace. In other words, I could neatly format my command by doing this:

That might be overkill, but you can see how the shell permits it, either in a script or even interactively at the command-line. Try it - at the command-line you'll get a >> prompt after typing { and hitting Enter. Continue typing exactly as shown here, and when you're done hit Enter on a blank >> prompt to execute the command.

So you CAN neatly-format your commands and code without having to drag that difficult-to-see backtick ` character into the picture.